Isolators for the gas-tight sectionalization of flues and ducts



Aug. 12, 1969 w, owe; ETAL ISOLATORS FOR THE GAS-TIGHT SECTIONALIZATION OF FLUES AND DUGTS Filed Aug. 18, 1967 5 Sheets-Sheet 1 Aug. 12, 198% w, M. LOWE ETAL 3,460,457

ISOLATORS FOR THE GAS-TIGHT SECTIONALIZATION OF FLUES AND DUCTS Filed Aug. 18. 1967 3 Sheets-Sheet 2 Aug. 12, 1969 w. M- LOWE ETAL 3,460,457

ISOLATORS FOR 'THE GAS-TIGHT SECTIONALIZATION 0F FLUES AND DUC'IS Filed Aug. 18. 1967 3 Sheets-Sheet 5 FIG].

3,460,457 ISOLATORS FOR THE GAS-TIGHT SECTIONAL- IZATION F FLUES AND DUCTS Walter Max Lowe and Frederick Squirrel], London, England, assignors to Thermo-Technical Development Limited, London, England, a British company Filed Aug. 18, 1967, Ser. No. 661,681

Int. Cl. F16k 3/02, 43/00 U.S. Cl. 98-1 11 Claims ABSTRACT OF THE DISCLOSURE An isolator of the sliding type for the gas-tight sectionalization of flues and ducts comprises a frame set across the flue and a sliding member moving into and out of the flue by way of an aperture in the frame structure. The sliding member in the closed position generally covers the flue cross section and in the open position the sliding member is fully extracted from the flue. Means are provided for cooperating with the frame for closing said aperture in the frame structure when the sliding member is in the extracted position.

This invention relates to isolators for the gas-tight sectionalization of flues and ducts.

The present invention consists in an isolator of the sliding type for the gas-tight sectionalization of flues and ducts comprising a frame set across the flue and a sliding member moving into and out of the flue by way of an aperture in the frame structure, the sliding member in the closed position generally covering the flue cross section and in which in the open position the sliding member is fully extracted from the flue and means cooperating with the frame for closing said aperture in the frame structure when the sliding member is in the extracted position.

Conveniently when the sliding member is provided with means whereby in the closed position it effects the closing of the said aperture.

The means for closing said aperture in the open position conveniently consist in a movable member, or members associated with the frame which will close the aperture when the sliding member is in the open position.

Conveniently also the slide is provided with the necessary flexible or resilient sealing means for providing a seal therearound in the closed position and these sealing means associated with the slide are withdrawn from the flue together with the slide in the open position so that they may be inspected or repaired.

The operating means for the slide will also be provided outside the flue so that they may be inspected or repaired without interruption of operations.

The invention will be further described with reference to the accompanying drawings.

FIGURE 1 is a front elevation of flue frame and sliding member according to the invention in the open position of the flue.

FIGURE 2 is a side elevation of the same.

FIGURE 3 is a section on the line III-III of FIG- URE 1 with the sliding member in the closed position.

FIGURE 4 is a section on the line IV-IV of FIG- URE 1.

FIGURE 5 is a cross section on the line VV of FIG- URE 1.

FIGURE 6 is a section on the line VIVI of FIG- URE 1.

FIGURES 7 and 8 are enlarged details of FIGURES l and 2 respectively.

In the drawings, the frame member 1 will be a permanent installation inthe flue. The sliding member 2 is adapted to be slid into or out of the frame through the States Patent 0 ice aperture 1a (FIGURE 6). The operating means are screws 1b at each side rotated from a common motor 10 and engaging nuts 1d (FIGURE 1) in a tube 1e (FIGURE 5) secured to the cross plate 2a of the sliding member.

Secured to the sliding member 2 are resilient flexible strips 2b, e.g. of alloy steel sheet which form a seal round the flue, e.g. on two sides by engaging in troughs 1 formed round the inner rim of the frame member 1.

The sliding member 2 at its upper and lower ends carries a loop seal extension 20 of resilient heat resistant alloy steel sheet which can form further seals for the sliding member in the closed position by abutting against the box girders 1g of the frame.

The sliding member 2 carries a pin 3 conveniently at the level of its lower side.

Along the top edge of the frame 1 there is mounted a sliding member 4 so as to be slidable across and to close the aperture 1a.

Sliding member 4 is fitted with loop springs of resilient heat resisting alloy steel across its lower face and secured at the ends to the side faces to form a compressible sealing pad 4a.

By means of a link 5 this sliding member 4 is connected with a bell-crank lever 6 pivotally mounted on the frame and comprising a jaw member 6a.

In operation from the open position of the flue the sliding member 4 is in a position closing the aperture 1a. As the sliding member 2 is lowered the pin 3 engages in the jaws 6a and turns the bell crank lever 6 from the position shown in FIGURE 6 to open the aperture 1a.

Rotation of the bell crank lever opens aperture 1a by sliding the member 4 to the right (in FIGURE 6) by means of the link 5.

When the sliding member 2 has been lowered into the flue closed position the upper loop seal 2c will abut the box girders 1g and close the aperture 1a (FIGURE 6).

Pins 3 with associated mechanisms 5, 6 may be located at each end of the slide 4.

The top entry arrangements described also incorporate dust clearing arrangements at the lower end.

Thus, a rod 7 is secured at its top end to the cross frame member 2d of the Sliding member 2 and at its lower end is fitted with a pin 8.

At the lower end of frame 1 there is provided an aperture 1h between box frame members 1g and this is arranged to be closed by a sliding box frame member 9.

Member 9 is fitted on its top face with a resilient pad 9a formed of sheets of heat-resistant alloy steel extending across the top face of member 9 and secured at their ends and the side faces adjacent the top edges. This pad 9a resiliently engages the under faces of box girders 1g on either side of gap 1h in the closed position.

To operate member 9 across the gap lb and to one side thereof there is provided the operating links 10 and 11 joined by a centrally pivoted cross member 12 with jaws 12a.

A jaw member 13 with jaws 13a is provided at the top of link 11.

In operation, as pin 8 descends it first engages jaws 13a and rotates the member 13 (clockwise in FIGURE 2) thereby depressing link 11 and turning lever 12 anticlockwise in FIGS. 2 and 7. This has the effect of raising link 10 which in turn moves the member 9 to the phantom position in FIGURE 3, opening the aperture 1h.

Air now rushes in and clears away any dust.

As the sliding member 2 descends further the pin 8 enters the jaws 12a and notches lever '12 clockwise in FIGURE 2, thus re-closing the aperture 1h by sliding the member 9 back across the aperture 1h.

Also in the closed position the cross-frame member 2d space 1k which is supplied with air from the fan 14.

Air from this space 1k passes around the sliding member through the spaces formed by the flanges If and seal ing members 2b and across the bottom along the gap 1h closed by the member 9.

A top entry system has been shown and described. In the case of a bottom entry system, the whole arrangement can be considered as invented but the slot lb and special dust clearing arrangements therefor will no longer be necessary; instead, as the top of the sliding member 2 enters the flue air will rush past it into the flue to clear away any dust accumulation.

We claim:

1. An isolator of the sliding type for the gas-tight sectionalization of flues and ducts comprising a frame structure adapted to be set across a flue and a. sliding member moving into and out of the flue by way of an aperture in the frame structure, flue sealing components attached to the sliding member, the sliding member in the closed position generally covering the flue cross section and in which in the open position the sliding member is fully extracted from the flue clear of the frame for access to the flue sealing components and means cooperating directly with the frame for closing said aperture in the frame structure when the sliding member is in the open position.

2. The isolator as claimed in claim 1, in which the sliding member is provided with means whereby in the closed position it effects the closing of said aperture.

3. The isolator as claimed in claim 2 in which the means for closing the aperture in the frame comprises a sliding member positively operated into and out of the aperture closing position by means operably related to the sliding member.

4. The isolator as claimed in claim 3, in which the aperture closing means is operated by means of a bell crank lever engaged by a pin reciprocating with the sliding memher.

5. The isolator as claimed in claim 1 m which the aperture is in the lower part of the frame structure and the sliding member enters itfrom below.

6. The isolator as claimed in claim 1, in which the aperture is in the top part of the frame structure and the sliding member enters it from above.

7. The isolator as claimed in claim 6, in which the lower part of the frame structure is provided with a second aperture and means for closing said aperture operable to open it as the sliding member approaches its closed position for the purpose of dust clearance and to close it again when the sliding member is fully closed.

8. The isolator as claimed in claim 1 in which the aperture closing means is provided with flexible resilient means for effecting a tight seal in its closed position.

9. The isolator as claimed in claim 8 in which the flexible resilient means comprises heat-resistant alloy steel sheet extending across the face of the aperture closing means and secured at each side thereto.

10. The isolator as claimed in claim 1 in which the frame structure on its entry side is provided with an air box having two apertures, with one leading into the flue and one leading to atmosphere and in which the sliding member is provided with means to etfect the closing of the atmospheric aperture of the air box when it is in its closed position.

11. The isolator as claimed in claim 10 whereby the sliding member is provided with means to close the atmospheric aperture of the air box when it is in its extracted position and with operating means for further extracting the sliding member to a servicing position where its sealing parts are fully accessible from outside.

References Cited UNITED STATES PATENTS 434,627 8/1890 Dewey 98-48 LLOYD L. KING, Primary Examiner U.S. Cl. X.R. 9848 

